Science

• lithosphere

  • made of the crust & the uppermost part of the mantle
• tectonic plates

  • interact & create tectonic activities on earth
• asthenosphere

  • below the lithosphere; contains magma
• convection currents

  • this drives the movement of tectonic plates
• crust

  • outermost layer of earth
• continental crust

  • made of light granitic rocks made out of mostly aluminum silicates
• oceanic crust

  • made of dense basaltic rocks made out of mostly magnesium silicates
• mantle

  • a semisolid part of the Earth's layers
• outer core

  • the only liquid part of the earth's layers
  • made of molten nickel & iron
• inner core

  • this layer of earth is mostly made of solid iron
• Mohorovicic discontinuity

  • interface between the crust & upper mantle
• Gutenberg discontinuity

  • marks the boundary between the lower mantle & outer core
• Lehmann discontinuity

  • located between the outer core & inner core
• seismometers

  • this instrument detects seismic waves
• seismograph

  • this records seismic waves
• body waves

  • these waves travel through the inner layers of the planet
• surface waves

  • only travel on the surface of the planet
• p waves

  • these waves are the first to be felt on Earth's surface
  • shakes the ground back & forth
  • pass through solid & liquid sections of earth
• s waves

  • also called transverse waves
  • moves particles in an up & down motion
  • slower than p waves
• Pangaea

  • the name of the supercontinent that means "all of earth"
• Panthalassa

  • this name means "all seas"
• contraction theory

  • this theory states that as Earth cooled down after its formation, its surface wrinkled, w/ these wrinkles being the mountain ranges on earth's surface
• theory of continental drift

  • this theory was made by Alfred Wegener
  • there was one a single landmass called Pangaea
• seafloor spreading theory

  • this theory states that the seafloors or ocean floors-- not the continents-- move & carry the continents along
  • this was coined by Harry Hess
• the seven major tectonic plates:

  • African plate
  • Indo-Australian plate
  • Antarctic plate
  • Eurasian Plate
  • Pacific plate
  • South American plate
  • North American plate
• the eight minor tectonic plates:

  • Juan de Fuca plate
  • Scotia plate
  • Caribbean plate
  • Philippine Sea plate
  • Nazca Plate
  • Cocos plate
  • Arabian plate
  • Indian plate
• driving forces

  • these forces either push tectonic plates toward one another or pull them apart
• mantle convection

  • this is caused by the rising of heat from the core toward the mantle
• slab pull

  • this takes place when a subducting slab sinks into the hot mantle because of a difference in temperature
• slab suction

  • occurs between two colliding plates, one subducting underneath the other, whereby convection currents in the upper mantle suck both plates down
• ridge push

  • occurs when the lithosphere is pushed up by the asthenosphere because of convection currents from the mantle
• resisting forces

  • these forces act against the driving forces of plate tectonics
• slab resistance

  • is the force that resists all the forces associated with plate movement in subduction zones
• collisional resistance

  • occurs when a heavy plate is pulled into the mantle but resists subduction because of friction
  • this opposes the slab pull
• transform fault resistance

  • is the frictional force due to the opposing movement of plates moving past one another between two spreading centers
• drag force

  • resists the movement of lithospheric plates
• Pacific Ring of Fire

  • a region in the Pacific ocean where most of the active volcanoes are found
• plate boundaries

  • these are the regions where tectonic plates meet
• divergent plate boundary

  • when two plates move away from each other & a gap between them is created
  • this forms rift valleys & mid-ocean ridges
• convergent plate boundary

  • occurs when two plates slide toward each other
  • forms either a subduction zone or an orogenic belt